Results 31 to 40 of about 15,587,481 (320)
On the positivity of solutions to the Smoluchowski equations [PDF]
Mathematika, 1995 The paper deals with positivity properties of solutions to Smoluchowski's coagulation equations, \[ \dot c_j = {1 \over 2} \sum^{j - 1}_{k = 1} a_{j - k,k} c_{j - k} c_k - c_j \sum^\infty_{k = 1} a_{j,k} c_k, \quad j = 1,2, \dots. \] It is proved that, with positive coefficients \(a_{j,k}\), the set \({\mathcal I} (t) : = \{j : c_j(t) > 0\}\) is ...
openaire +3 more sources
Positive solutions of integrodifferential equations [PDF]
International Journal of Stochastic Analysis, 1992 Integrodifferential equations of the forms urn:x-wiley:20903332:media:ista345783:ista345783-math-0001 are considered, where K ∈ C([0, ∞), [0, ∞)), p ∈ C([0, ∞), [0, ∞)) and q ∈ C((−∞, ∞), [0, ∞)). Necessary conditions and also sufficient conditions for the existence of positive solutions are established.
openaire +3 more sources
Positive solutions for asymptotically linear problems in exterior domains
, 2016 The existence of a positive solution for a class of asymptotically lin- ear problems in exterior domains is established via a linking argument on the Nehari manifold and by means of a barycenter ...
Maia, Liliane A., Pellacci, Benedetta
core +1 more source
The unpredictably eruptive dynamics of spruce budworm populations in eastern Canada
Population Ecology, EarlyView.We examine historical population data for spruce budworm from several locations through the period 1930–1997, and use density‐dependent recruitment curves to test whether the pattern of population growth over time is more consistent with Royama's (1984; Ecological Monographs 54:429–462) linear R(t) model of harmonic oscillation at Green River New ...
Barry J. Cooke, Jacques Régnière
wiley +1 more source
Positive Solutions of Nonlinear Elliptic Eigenvalue Problems [PDF]
, 1970 We shall study a class of mildly nonlinear elliptic eigenvalue problems which are suggested by several recently occurring problems concerning the steady state temperature distribution of a physical medium in which heat is being generated ...
Cohen, Donald S., Simpson, R. Bruce
core
Constructing polynomial systems with many positive solutions using tropical geometry
, 2017 The number of positive solutions of a system of two polynomials in two variables defined in the field of real numbers with a total of five distinct monomials cannot exceed 15. All previously known examples have at most 5 positive solutions.
Hilany, Boulos El
core +1 more source
Network topology drives population temporal variability in experimental habitat networks
Population Ecology, EarlyView.Habitat patches connected by dispersal pathways form habitat networks. We explored how network topology affects population outcomes in laboratory experiments using a model species (Daphnia carinata). Central habitat nodes in complex lattice networks exhibited lower temporal variability in population sizes, suggesting they support more stable ...
Yiwen Xu +3 more
wiley +1 more source
Existence of Positive Solutions for fourth-order Differential Equations with indeterminate weights [PDF]
, 2018 In this paper, the existence of positive solutions of fourth-order differential equations with indeterminate weights is considered as ...
Wang, J. (Jiao)
core
On positive solutions and the Omega limit set for a class of delay differential equations
, 2012 This paper studies the positive solutions of a class of delay differential equations with two delays. These equations originate from the modeling of hematopoietic cell populations. We give a sufficient condition on the initial function for $t\leq 0$ such
B. Dorizzi +15 more
core +1 more source
occumb: An R package for site occupancy modeling of eDNA metabarcoding data
Population Ecology, EarlyView.This study introduces a new R package, occumb, for the convenient application of site occupancy modeling using environmental DNA (eDNA) metabarcoding data. We outline a data analysis workflow, including data setup, model fitting, model assessment, and comparison of potential study settings based on model predictions, all of which can be performed using
Keiichi Fukaya, Yuta Hasebe
wiley +1 more source